Electrolyte‐Free Cathode Design for High‐Sulfur‐Loading All‐Solid‐State Li‐S Batteries

ABSTRACT All‐solid‐state lithium‐sulfur batteries (ASSLSBs) with polymer electrolytes have high theoretical energy density and improved safety, providing appealing potential for next‐generation energy storage. However, limiting the dissolution of long‐chain polysulfides (LiPSs) in polymer electrolyte and achieving high S loading in cathodes remains a challenge. To tackle this issue, we demonstrate a 3D electrode composed of a mixture of styrene butadiene rubber and lithium carboxyl methyl cellulose as the binder, equipped with a high concentration of all‐solid‐state polyethylene oxide (PEO) ‐based electrolyte filled with LLZTO (Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 ) and LiPSs (named LiPS/LLZTO‐CL/S). The synergistic design exhibits outstanding structural stability, preventing the dissolution of long‐chain LiPSs, enhancing the kinetics of short‐chain LiPSs, alleviating volume expansion, and offering pathways for ion/electron transport. The battery possesses attractive cycling stability and can maintain high capacity retention (1106 mAh g −1 even after 500 cycles) at 0.2 C. Its structural and electrochemical advantages enable stable cycling at a high sulfur loading of 7.0 mg cm −2 and 0.5 C without electrolyte in the cathode. This work proposes a novel strategy for the structural design of high‐loading polymer ASSLSBs.